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Mathematical Modeling of the Dynamics of Shoot-Root Interactions and Resource Partitioning in Plant Growth.

Feller C, Favre P, Janka A, Zeeman SC, Gabriel JP, Reinhardt D - PLoS ONE (2015)

Bottom Line: Our main goal was to grasp the dynamic adaptation of shoot:root ratio as a result of changes in light and Pi supply.The results of our study are in agreement with balanced growth hypothesis, suggesting that plants maintain a functional equilibrium between shoot and root activity based on differential growth of these two compartments.Furthermore, our results indicate that resource partitioning can be understood as the emergent property of many local physiological processes in the shoot and the root without explicit partitioning functions.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Mathematics, University of Fribourg, Fribourg, Switzerland.

ABSTRACT
Plants are highly plastic in their potential to adapt to changing environmental conditions. For example, they can selectively promote the relative growth of the root and the shoot in response to limiting supply of mineral nutrients and light, respectively, a phenomenon that is referred to as balanced growth or functional equilibrium. To gain insight into the regulatory network that controls this phenomenon, we took a systems biology approach that combines experimental work with mathematical modeling. We developed a mathematical model representing the activities of the root (nutrient and water uptake) and the shoot (photosynthesis), and their interactions through the exchange of the substrates sugar and phosphate (Pi). The model has been calibrated and validated with two independent experimental data sets obtained with Petunia hybrida. It involves a realistic environment with a day-and-night cycle, which necessitated the introduction of a transitory carbohydrate storage pool and an endogenous clock for coordination of metabolism with the environment. Our main goal was to grasp the dynamic adaptation of shoot:root ratio as a result of changes in light and Pi supply. The results of our study are in agreement with balanced growth hypothesis, suggesting that plants maintain a functional equilibrium between shoot and root activity based on differential growth of these two compartments. Furthermore, our results indicate that resource partitioning can be understood as the emergent property of many local physiological processes in the shoot and the root without explicit partitioning functions. Based on its encouraging predictive power, the model will be further developed as a tool to analyze resource partitioning in shoot and root crops.

No MeSH data available.


Related in: MedlinePlus

Simulation of the competing effects of limited light irradiance and Pi starvation on plant growth and root fraction.Growth of the shoot (A,D) and the root (B,E), as well as the resulting root fraction (C,F) are given for six light levels between 100 and 400 μmol m-2 s-1 (I = 200 μmol m-2 s-1) at high Pi levels of 300 μM (A-C) and Pi starvation conditions at 10 μM (D-F).
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pone.0127905.g009: Simulation of the competing effects of limited light irradiance and Pi starvation on plant growth and root fraction.Growth of the shoot (A,D) and the root (B,E), as well as the resulting root fraction (C,F) are given for six light levels between 100 and 400 μmol m-2 s-1 (I = 200 μmol m-2 s-1) at high Pi levels of 300 μM (A-C) and Pi starvation conditions at 10 μM (D-F).

Mentions: Next we tested the relative sensitivity of the model to combined changes in the exogenous cues light and phosphate under yet unexplored conditions. We first simulated growth at various light conditions from 100 μmol m−2 s−1 to 400 μmol m−2 s−1, and these simulations were carried out at two different Pi levels of 10 μM and 300 μM, corresponding to Pi starvation and to saturating Pi levels, respectively. At high Pi supply, low light levels (100 and 200 μmol m−2 s−1) caused shoot growth to become decreased (Fig 9A), however, the effect on root growth was much more dramatic (Fig 9B), leading to strong reductions of root fraction at all light levels below the maximum of 400 μmol m−2 s−1 (Fig 9C). If plants were in addition exposed to Pi starvation, the inhibiting effect of low light on root growth was much less pronounced (Fig 9E), and the resulting decrease in root fraction was weaker (Fig 9F). These results show that the model exhibits realistic global behaviour under combined environmental changes of light and nutrients.


Mathematical Modeling of the Dynamics of Shoot-Root Interactions and Resource Partitioning in Plant Growth.

Feller C, Favre P, Janka A, Zeeman SC, Gabriel JP, Reinhardt D - PLoS ONE (2015)

Simulation of the competing effects of limited light irradiance and Pi starvation on plant growth and root fraction.Growth of the shoot (A,D) and the root (B,E), as well as the resulting root fraction (C,F) are given for six light levels between 100 and 400 μmol m-2 s-1 (I = 200 μmol m-2 s-1) at high Pi levels of 300 μM (A-C) and Pi starvation conditions at 10 μM (D-F).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495989&req=5

pone.0127905.g009: Simulation of the competing effects of limited light irradiance and Pi starvation on plant growth and root fraction.Growth of the shoot (A,D) and the root (B,E), as well as the resulting root fraction (C,F) are given for six light levels between 100 and 400 μmol m-2 s-1 (I = 200 μmol m-2 s-1) at high Pi levels of 300 μM (A-C) and Pi starvation conditions at 10 μM (D-F).
Mentions: Next we tested the relative sensitivity of the model to combined changes in the exogenous cues light and phosphate under yet unexplored conditions. We first simulated growth at various light conditions from 100 μmol m−2 s−1 to 400 μmol m−2 s−1, and these simulations were carried out at two different Pi levels of 10 μM and 300 μM, corresponding to Pi starvation and to saturating Pi levels, respectively. At high Pi supply, low light levels (100 and 200 μmol m−2 s−1) caused shoot growth to become decreased (Fig 9A), however, the effect on root growth was much more dramatic (Fig 9B), leading to strong reductions of root fraction at all light levels below the maximum of 400 μmol m−2 s−1 (Fig 9C). If plants were in addition exposed to Pi starvation, the inhibiting effect of low light on root growth was much less pronounced (Fig 9E), and the resulting decrease in root fraction was weaker (Fig 9F). These results show that the model exhibits realistic global behaviour under combined environmental changes of light and nutrients.

Bottom Line: Our main goal was to grasp the dynamic adaptation of shoot:root ratio as a result of changes in light and Pi supply.The results of our study are in agreement with balanced growth hypothesis, suggesting that plants maintain a functional equilibrium between shoot and root activity based on differential growth of these two compartments.Furthermore, our results indicate that resource partitioning can be understood as the emergent property of many local physiological processes in the shoot and the root without explicit partitioning functions.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Mathematics, University of Fribourg, Fribourg, Switzerland.

ABSTRACT
Plants are highly plastic in their potential to adapt to changing environmental conditions. For example, they can selectively promote the relative growth of the root and the shoot in response to limiting supply of mineral nutrients and light, respectively, a phenomenon that is referred to as balanced growth or functional equilibrium. To gain insight into the regulatory network that controls this phenomenon, we took a systems biology approach that combines experimental work with mathematical modeling. We developed a mathematical model representing the activities of the root (nutrient and water uptake) and the shoot (photosynthesis), and their interactions through the exchange of the substrates sugar and phosphate (Pi). The model has been calibrated and validated with two independent experimental data sets obtained with Petunia hybrida. It involves a realistic environment with a day-and-night cycle, which necessitated the introduction of a transitory carbohydrate storage pool and an endogenous clock for coordination of metabolism with the environment. Our main goal was to grasp the dynamic adaptation of shoot:root ratio as a result of changes in light and Pi supply. The results of our study are in agreement with balanced growth hypothesis, suggesting that plants maintain a functional equilibrium between shoot and root activity based on differential growth of these two compartments. Furthermore, our results indicate that resource partitioning can be understood as the emergent property of many local physiological processes in the shoot and the root without explicit partitioning functions. Based on its encouraging predictive power, the model will be further developed as a tool to analyze resource partitioning in shoot and root crops.

No MeSH data available.


Related in: MedlinePlus